Investigating the Potential of Utilizing Free Standing Bi1−xGdxFeO3 Polymer-Ceramic Nanocomposite Film for Applications in Flexible and Wearable Microwave Devices

Abstract

A facile approach was developed for a novel polymer-ceramic nanocomposite, specifically gadolinium-substituted bismuth ferrites (Bi_1−xGd_xFeO₃) for flexible radio-frequency (RF) antenna applications. The polymer-ceramic nanocomposite was developed by synthesizing gadolinium-substituted bismuth ferrite (Bi_1−xGd_xFeO₃) nanoparticles through a methoxy-aided sol–gel process followed by dispersion in PVA polymer. The structural and morphological characteristics of the nanoparticles were extensively examined using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The study revealed a rhombohedral distorted perovskite structure and increased crystallite size with higher gadolinium concentrations. Dielectric properties of the nanocomposite material was investigated at low and high frequencies to assess the material’s suitability for high-frequency conformal antennas. The PVA/Bi_0.9Gd_0.1FeO₃ nanocomposite films exhibited a relative wave impedance of 0.6 with a miniaturization factor of 1.89 making it eligible for microwave device applications. The microstrip patch antenna modeled and simulated with the PVA/Bi_0.9Gd_0.1FeO₃ composite exhibited a return loss of − 21.9 dB in the X band of the frequency spectrum. The functionality of the antennas was tested for the bending conditions of radius 10 mm and 30 mm, exhibiting a return loss of − 41.2 dB and − 23.5 dB in the X band with an ultrawide bandwidth of 5 GHz. The results of PVA/Bi_0.9Gd_0.1FeO₃ nanocomposite substrate antennas exhibit enhanced performance for application in wireless wearable devices.